Two slides - one unifying diagnosis

This ulcer was found on the lesser curve of a middle aged man with dyspepsia.  Biopsies are taken and stained with H&E (below)

WHAT IS THE AETIOLOGY OF THAT GU? 

■ Benign GU

Don't you think that the mucosa look odd near to the ulcer?

■ Lymphoma

Yes! That odd atrophic mucosa next to the ulcer look weird but not "carcinoma weird" !

■ Adenocarcinoma - intestinal type

With a 'standard cancer', the surrounding mucosa should be thickened and red not atrophic looking

■ Adenocarcinoma - intestinal type

This was actually my own diagnosis but histology shows lots of small round lymphocytes not ballooned up signet ring cells.

EXPLANATION

There are only two possibilities here.   Of course the ulcer itself doesn't tell you much. The mucosa surrounding the ulcer tells you more!   With a benign ulcer, you would expect a thin rim of 'reactive' mucosa (looks red and a little villous).  In the case of an intestinal type of adenocarcinoma a broad band of surrounding mucosa is red, indurated and thickened.   In gastric lymphomas, the surface area of abnormal mucosa is usually far greater than the surface area of the ulceration.  There are usually areas of atrophic and inflamed mucosa.   Mucosa infiltrated by a diffuse type adenocarcinoma could look like this BUT it's unusual for it to ulcerate!     

This patient has a MALT lymphoma !  Of course, I took samples for Helicobacters.  Of course not every MALT lymphoma is linked with HP infection (about 2/3 cases are though).  

In this case our haematologists were optimistic of a good response to Hp eradication because all the 3 good prognostic criteria were met:

1. Only involvement of the mucosa (with no evidence of extension into the muscularis propria)
2. No nodal disease on CT
3. No 'unfavourable' mutations (such as translocations causing deregulation of MALT1 or Bcl-10 such as T(11;18), or overexpression of miR-142-5p and miR-155.